Hiccups are repeated involuntary spasms of the diaphragm, followed by quick, noisy closings of the glottis. The diaphragm is the muscle that separates the chest from the abdomen and that is responsible for each breath. The glottis is the opening between the vocal cords, which closes to stop the flow of air to the lungs. Hiccups are more common among men.

Brief episodes of hiccups (lasting a few minutes) are very common. Occasionally, hiccups persist for some time, even in healthy people. Sometimes hiccups can last more than 2 days or even more than 1 month. These longer episodes are called persistent or intractable (difficult to treat or cure). These longer episodes are uncommon but can be quite distressing.

Causes of Hiccups

Doctors are not clear why hiccups happen but they think it may involve irritation of the nerves or the parts of the brain that control muscles of respiration (including the diaphragm).

Brief episodes of hiccups often have no obvious cause but sometimes are triggered by

A bloated stomach

Alcohol consumption

Swallowing hot or irritating substances

In such cases, hiccups usually start in a social situation, perhaps triggered by some combination of laughing, talking, eating, and drinking (particularly alcohol). Sometimes hot or irritating food or liquids are the cause. Hiccups are more likely to occur when carbon dioxide levels in the blood decrease. Such a decrease can occur when people hyperventilate.

Persistent or intractable episodes of hiccups sometimes have more serious causes (see Table: Some Causes and Features of Persistent or Intractable Hiccups). For example, the diaphragm may become irritated because of pneumonia, chest or stomach surgery, or waste products that accumulate in the blood when the kidneys malfunction (uremia). Rarely, hiccups develop when a brain tumor or stroke interferes with the breathing center in the brain.

When the cause is serious, hiccups tend to persist until the cause is corrected. Hiccups due to a brain tumor or stroke may be very hard to stop and may become exhausting.

Evaluation of Hiccups

Brief episodes of hiccups do not require evaluation by a doctor. For persistent hiccups, the following information can help people decide whether a doctor’s evaluation is needed and help them know what to expect during the evaluation.

Warning signs

In people with hiccups, certain symptoms and characteristics are cause for concern. They include

When to see a doctor

People who have hiccups and warning signs should see a doctor right away. People without warning signs should see a doctor if hiccups last more than 2 or 3 days.

What the doctor does

Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What doctors find during the history and physical examination often suggests a cause of the hiccups and the tests that may need to be done (see Table: Some Causes and Features of Persistent or Intractable Hiccups).

The history is focused on how long the hiccups have lasted, what remedies the person has tried, and whether the person has recently been ill or had surgery. Doctors also ask people whether they have any

The physical examination is focused on a full neurologic examination. A general examination usually does not reveal much, but doctors look for signs of chronic disease such as severe wasting away of muscle and fat tissue (cachexia).

*Features include symptoms and the results of the doctor's examination. Features mentioned are typical but not always present.

CT = computed tomography; MRI = magnetic resonance imaging.

Testing

Doctors generally do not do any testing for people who have brief hiccups.

People who have warning signs or whose hiccups are persistent and have no obvious cause should have testing. Doctors typically begin with blood tests, chest x-rays, and electrocardiography (ECG). Other tests are done based on the other symptoms people have (see Table: Some Causes and Features of Persistent or Intractable Hiccups). If these tests do not reveal a cause, doctors may do magnetic resonance imaging (MRI) of the brain and computed tomography (CT) of the chest even if people do not have other symptoms specifically related to these areas.

Treatment of Hiccups

The best way to treat hiccups is to treat the underlying disorder. For example, doctors give people antibiotics for pneumonia and proton pump inhibitors for gastroesophageal reflux disease.

Brief hiccups

Nearly all hiccups go away with or without treatment. Many home remedies have been used to treat brief hiccups. Most do not work or are only slightly effective. However, because these remedies typically are safe and simple to do, there is no harm in trying them. Many methods involve ways to raise the level of carbon dioxide in the blood, such as the following:

Holding the breath

Breathing deeply into a paper (not plastic) bag

Other methods are done to try to stimulate the vagus nerve, which runs from the brain to the stomach. The following can stimulate this nerve:

Drinking water quickly

Swallowing dry bread, granulated sugar, or crushed ice

Gently pulling on the tongue

Stimulating gagging (such as by sticking a finger down the throat)

Gently rubbing the eyeballs

Persistent and intractable hiccups

For persistent hiccups, treatment is needed, particularly when the cause cannot be easily corrected. Several drugs have been used with varying success. They include but are not limited to chlorpromazine, baclofen, metoclopramide, and gabapentin.

If drugs do not work, doctors may block one of the phrenic nerves, which control the contractions of the diaphragm. Doctors block the nerve by injecting it with small amounts of a local anesthetic called procaine. If blocking the nerve works but hiccups return, doctors may surgically cut the nerve (phrenicotomy), but even this procedure does not cure all cases.

Key Points

The cause is usually unknown.

Although rare, a serious disorder is sometimes present.

A doctor’s evaluation typically does not reveal a cause but should be done for hiccups that are persistent or intractable.

Numerous remedies exist, but none is superior to or more effective than the other ones.

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